package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
@Slf4j
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Autowired
    private IUserService userService;
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    @Autowired
    private IFollowService followService;

    /**
     * @param current
     * @return
     */
    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));

        List<Blog> records = page.getRecords();
        records.forEach(blog ->{

            queryBlogUser(blog);
            isBlogLiked(blog);
        });
        log.info("records:{}",records);
        return Result.ok(records);
    }

    /**
     * @param id
     * @return
     */
    @Override
    public Result queryBlogLikes(Long id) {
       String blogLikeKey = RedisConstants.BLOG_LIKED_KEY + id;
        // 1.查询top5的点赞用户 zrange key 0 4
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(blogLikeKey, 0, 4);
        if (top5 == null || top5.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }
        List<Long> userIdList = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String userIdStr = StrUtil.join(",", userIdList);
        // 2.根据用户id查询用户 where id in ( 5, 1 ) order by field(id, 5, 1)
        List<UserDTO> userList = userService.query().
                in("id", userIdList).
                last("ORDER BY FIELD(id," + userIdStr + ")").
                list().stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());
        return Result.ok(userList);
    }

    /**
     * @param blog
     * @return
     */
    @Override
    public Result saveBlog(Blog blog) {
        // 1.获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 2.保存探店博文
        boolean isSuccess = save(blog);
        if (!isSuccess) {
            return Result.fail("新增笔记失败！");
        }
        // 3.查询笔记作者的所有粉丝 select * from tb_follow where follow_user_id =?
        List<Follow> followList = followService.query().eq("follow_user_id", user.getId()).list();
        long currentTimeMillis = System.currentTimeMillis();
        followList.forEach(follow -> {
            Long userId = follow.getUserId();
            // 4.推送笔记id给所有粉丝
            String key = RedisConstants.FEED_KEY + userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(), currentTimeMillis);
        });
        // 5.返回id
        return Result.ok(blog.getId());

    }

    /**
     * @param max
     * @param offset
     * @return
     */
    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        // 1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        // 2.查询收件箱 ZREVRANGEBYSCORE key MAX MIN LIMIT offset count
        String key = RedisConstants.FEED_KEY + userId; //feed:id
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.
                opsForZSet().
                reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        if (typedTuples == null || typedTuples.isEmpty()) {
            return Result.ok();
        }
        // 4.解析数据：blogId、minTime（时间戳）、offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for (ZSetOperations.TypedTuple<String> tuple : typedTuples) { 
            // 4.1.获取id
            String value = tuple.getValue();
            ids.add(Long.valueOf(value));
            // 4.2.获取分数(时间戳)
            long time = tuple.getScore().longValue();
            if (time == minTime) {
                os++;
            }else {
                minTime = time;
                os = 1;
            }
        }
        os = minTime == max ? os : os + offset;

        // 5.根据id查询blog
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list();

        for (Blog blog : blogs) {
            // 5.1.查询blog有关的用户
            queryBlogUser(blog);
            // 5.2.查询blog是否被点赞
            isBlogLiked(blog);
        }

        // 6.封装并返回
        ScrollResult scrollResult = new ScrollResult();
        scrollResult.setList(blogs);
        scrollResult.setOffset(os);
        scrollResult.setMinTime(minTime);

        return Result.ok(scrollResult);

    }

    /**
     * @param id
     * @return
     */
    @Override
    public Result queryBlogById(Long id) {
        // 1.查询blog
        Blog blog = getById(id);
        if (blog == null) {
            return Result.fail("笔记不存在！");
        }
        // 2.查询blog有关的用户
        queryBlogUser(blog);
        // 3.查询blog是否被点赞
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    private void isBlogLiked(Blog blog) {
        if (Objects.isNull(UserHolder.getUser())){
            blog.setIsLike(false);
        }else{
        Long userId = UserHolder.getUser().getId();
        //判断当前登录用户是否已经点赞
        String key = RedisConstants.BLOG_LIKED_KEY + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score!= null);
        }
    }
    /*private void isBlogLiked(Blog blog) {
        Long userId = UserHolder.getUser().getId();
        //判断当前登录用户是否已经点赞
        String key = RedisConstants.BLOG_LIKED_KEY + blog.getId();
        Boolean member = stringRedisTemplate.opsForSet().isMember(key, userId.toString());
        blog.setIsLike(BooleanUtil.isTrue(member));
    }*/

    /**
     * 点赞博客
     * @param id
     * @return
     */
    @Override
    public Result likeBlog(Long id) {
        Long userId = UserHolder.getUser().getId();

        String blogLikeKey = RedisConstants.BLOG_LIKED_KEY + id;
        // 1.判断当前登录用户是否已经点赞
//        Boolean member = stringRedisTemplate.opsForSet().isMember(blogLikeKey, userId.toString());
        Double score = stringRedisTemplate.opsForZSet().score(blogLikeKey, userId.toString());
        if (Objects.nonNull(score)) {
            // 2.如果已点赞，取消点赞
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            // 3.删除点赞记录
            stringRedisTemplate.opsForZSet().remove(blogLikeKey,userId.toString());
        } else {
            // 3.如果未点赞，添加点赞
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            // 4.
            if (isSuccess){
                stringRedisTemplate.opsForZSet().add(blogLikeKey,userId.toString(),System.currentTimeMillis());
            }
        }
        return Result.ok();
    }
    /*    @Override
    public Result likeBlog(Long id) {
        Long userId = UserHolder.getUser().getId();

        String blogLikeKey = RedisConstants.BLOG_LIKED_KEY + id;
        // 1.判断当前登录用户是否已经点赞
        Boolean member = stringRedisTemplate.opsForSet().isMember(blogLikeKey, userId.toString());
        if (member) {
            // 2.如果已点赞，取消点赞
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            // 3.删除点赞记录
            stringRedisTemplate.opsForSet().remove(blogLikeKey,userId.toString());
        } else {
            // 3.如果未点赞，添加点赞
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            // 4.保存用户到Redis的set集合
            stringRedisTemplate.opsForSet().add(blogLikeKey,userId.toString());
        }
        return null;
    }*/



    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}
